Classic 50 Running Issues

[armkb]

I have a 1988 "Classic 50" 45 HP Mercury on a 1987 Princecraft 16' Pro V-Hull.
Bought last summer and ran well up to a few weeks ago. The motor starts well but when it is cold and damp it will not go to full throttle. Doesnt seem to be missing. When it is warmed up after about 10 minutes or so it will go to full throttle. When it is warming up I can hear and feel it trying to rev up but it just hangs back. I did find a white wire going from the switch box to the underside of the flywheel that had dried and lost most of its insulation. I cut it back as far as I could and spliced in a new wire thinking it would solve the problem, but it still persists. Does anyone have any ideas where I should be looking? Thanks for your input!!

 

[armkb]

Re: Classic 50 Running Issues

anyone!!!

 

[Laddies]

Re: Classic 50 Running Issues

That problem is very common as a switch box goes bad, there is really know test for a box other than checking input and output voltage with a DVA but you can check for spark with a spark gap when the engine is acting up.

 

[armkb]

Re: Classic 50 Running Issues

Any idea why it would act up only when cold, and seem fine when it is up to temp. I thought resistance increases with temperature increase, then why would the switch box work when warmed up. The white wire that is losing its insulation is coming from the trigger switch under the flywheel and goes to the switch box and to the number 2 cylinder, and I did notice that the plug for the number 2 cylinder was very clean once...almost new looking...hence it may not be firing when cold.

 

[Laddies]

Re: Classic 50 Running Issues

Resisitance readings have nothing to do with the box only the windings in the stator and trigger. The only way to to test the box is with a DVA and check input and output voltage to see what is not working when cold.